MUSKEGON, Mich.--Tucked in the back corner of a nondescript office park is an early shoot in the budding green-energy economy--a start-up with big plans for small wind turbines.

Last month, I took a detour from a summer road trip to visit WindTronics and see a prototype of its wind turbine designed for individual homes and commercial buildings. The company's lab, housed in a nearly empty warehouse, is a glimpse into the fervent experimentation going on among green-tech entrepreneurs and, specifically, in small wind.

Despite all the activity, there's some creeping doubt about the ultimate potential of small wind. A study in Massachusetts and one in the U.K. found that many residential locations don't have sufficient wind to meet the promised output of small turbines.

In WindTronics' lab, a protoype of the Honeywell Wind Turbine, which is 6 feet tall and weighs 95 pounds.
Martin LaMonica/CNET

WindTronics has designed a turbine that addresses that wind speed issue head on. While most wind turbines start to work when the wind blows at seven or eight miles per hour, its machine--to be sold for $4,500 as the Honeywell Wind Turbine--starts to generate electricity at only two miles per hour. That, say company executives, means small wind can make sense economically in many more locations.

Kilowatts versus kilowatt-hours
Entering WindTronics' lab, there wasn't much to see except for a spartan office and conference room. A design drawing of its wheel-like turbine on the wall gave me a clue I was in the right place. After a moment, the turbine's inventor and chief technical officer, Imad Mahawili, greeted me and brought me into a warehouse.

At the back end of the cavernous room, there was the 6-foot-high turbine, a table with some testing equipment, and a truck trailer that had been converted into a low-cost wind tunnel.

WindTronics has designed its turbine, which is now going through certification testing and will be available later this year, to be mounted on rooftops or onto free-standing poles. The most striking thing about seeing the turbine up close is how big it is. At 6 feet high without the mounting gear, it would be a conspicuous addition on a home's roofline, although I imagine less so on a pole.

The turbine is built around a wheel with long spokes, each of which has a specially shaped, bendable nylon blade attached to it. Around the rim of this big wheel is a "shroud" that covers the blade edges. This is where WindTronics' design differs from most other wind machines.

Most turbines have a gear box at the hub of the rotor. As the wind turns the blades, the gear box turns a generator to make electricity.

WindTronics turns things inside out by having the electricity generation happen at the rim of the turbine. Permanent magnets attached to the blade tips spin past stators--essentially wire coils--attached to the shroud to generate a current. Without the resistance of a gear box at the hub, WindTronics says its turbine will spin--and generate electricity--at low wind speeds, which over the course of time will add up to more power than other turbines, company executives argue.

"The reality is because most turbine makers sell to utilities, they have to specify the maximum power," said Mahawili. "The other companies don't give details on how many kilowatt-hours a turbine will make, just the plate power (in kilowatts), which doesn't signify much. We're really not telling the story as we should."

WindTronics says its turbine will generate 2,000 kilowatt-hours in a year for a home with a very good--called Class 4--wind resource. That's between 15 and 20 percent of the annual electricity consumption for the average U.S. home.

Green collar industry?
Mahawili then cranked up the wind tunnel, which is used to measure the output of the turbine. Rather than pay a lot of money to test its turbines in commercial wind tunnels, it built its own with a giant fan placed at the front of a semi trailer.

As the fan cranked up, we could see on a laptop how much power the test turbine produced at different speeds. With about 10 mile-per-hour wind, it generated about 100 watts and kept climbing upward with higher speeds.

Part of its system for capturing wind power at low speeds is a battery--a standard issue 12-volt car battery--that stores electricity at very low wind speeds. As it speeds up, the turbine can directly feed an inverter to produce household current, Mahawili explained.

When I walked into the wind tunnel itself, there was no noticeable vibration. The fan for the wind tunnel made noise but I couldn't distinguish the sound of the WindTronics test turbine, which the company says will operate very quietly at 35 to 45 decibels.

After the wind tunnel slowed down, WindTronics CEO Reg Adams told me about the company's business plans. It has a partnership with Ace Hardware to distribute the turbine starting this fall. The first units will be manufactured in the Netherlands but the company is looking for factory sites in the U.S.

There are already tax incentives offered from Michigan, a state that's desperately seeking out new manufacturing industries, notably wind. WindTronics was incubated in the Michigan Alternative and Renewable Energy Center in Muskegon, a city known in the past for its lumber industry.

Although it has the support of government officials plugging for "green-collar jobs," WindTronics has a long way to go before it can claim to be a commercial success. In addition to finalizing its product, it has to develop the distribution channels and ensure enough people are trained to install the turbines.

Also, the small wind category is relatively immature. Although there was a big jump in sales last year, there were only 10,000 units installed, according to the American Wind Energy Association. Even with its ability to spin at low speeds, WindTronics' turbine should be placed in good locations for wind, said president and CEO Reg Adams. Typically, that means well above and away from any obstructions, including trees, in a site with steady wind.

Still, the company's goal is to bring the cost of distributed wind down significantly and get a toehold in this relatively new market. When compared to other turbines or solar panels, the yearly energy output of WindTronics' turbine will compare favorably on price, said Adams. "We want this to be mainstream, not a specialty item," he said.

About the author

Martin LaMonica is a senior writer covering green tech and cutting-edge technologies. He joined CNET in 2002 to cover enterprise IT and Web development and was previously executive editor of IT publication InfoWorld.
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